I just found that if you clear your calendar cache on the phone, I don't get that error anymore! And I did a test appt on my phone, and it automatically synced to my google calendar on my pc.
settings ->applications -> manage applications -> calendar storage -> clear cache
Hope that helps.
Sadly I must state that I, too, get the calendar crash every time I use any app that touches the calendar...Gemini Calendar, Daily Briefing, and Ringer Genie. Following the suggestion to clear the cache doesn't seem to help as it is empty and all buttons are grayed out.
Since I've had non-stop crashes with Kies on my Windows 7 Enterprise system (MainStage crash EVERY time I start it), I installed a system called DejaOffice and it seems to work out just fine. Of course this is because it has its own calendar system, but the auto-profile program (Ringer Genie was the only program I found that could do what I need) no longer works.
Has anyone found a solution to fixing the calendar issue for Froyo 2.2.1? I'd hate to have to revert to 2.2.
Thanks in advance.
Cole